[Fertility in mares after an disturbed as well as an undisturbed puerperium. Significance of histological and cytological examinations of the uterus].

The research article discusses the effect of disturbed and undisturbed postpartum period (puerperium) on the fertility of mares, highlighting the importance of uterine examinations for assessing fertility. The authors recommend that the first postpartum oestrus should not be used for breeding, particularly in cases with complications like retained placenta, due to their observation of significantly lower fertility rates.

Overview of the Study

• The study is based on the biological ability of mares (female horses) to conceive shortly after giving birth. Because of this, it’s crucial to closely monitor the postpartum period, also known as the puerperium.
• The researchers used cytological examinations of uterine content and histological examinations of uterine biopsy specimens as tools for monitoring. They found these methods provided more detailed information compared to microbiological examinations of uterine swabs.
• The sample consisted of 55 mares, whose uterine content and uterus biopsy specimens were histologically examined on the 3rd, 6th, and 9th days following birth.

Findings of the Study

• Disturbed postpartum processes, particularly cases of retained placenta, resulted in a heavy reaction involving large numbers of white blood cells (polymorphonuclear leukocytes) in the layer lining the uterus (endometrium).
• This reaction, along with a delayed regeneration of the uterine epithelium and the uterine gland epithelium, led to significantly lower fertility rates during the first postpartum oestrus (heat cycle).
• From these observations, the researchers recommend against using the first postpartum heat for breeding.

Implications of the Study

• The study underscores the importance of monitoring the puerperium in mares due to the potential impact on fertility. Histological and cytological examinations are highlighted as reliable strategies for monitoring.
• Findings suggest that mating during the first postpartum heat, especially when complications such as retained placenta are observed, may not be successful due to reduced fertility.
• This research can help horse breeders and veterinarians improve horse breeding strategies by providing a more careful and detailed assessment of mares following birth.